Digital data representative of X-Y point coordinates and lines are often inputted into microcomputers through the use of digitizer pads and digitizer pens. The digitizer pads are pressure sensitive, so that X-Y data is inputted into the computer as a function of the position upon the surface of the pad which receives pressure from the pen. For example, if the operator is inputting data indicative of a straight line starting from X-1, Y-1 and terminating at X-2, Y-2, the operator points with a pen at a point upon the surface of the digitizer pad corresponding to X-1, Y-1, and presses down upon this point, with the digitizer pen, and thereafter repeats the process with respect to X-2, Y-2. The computer may be programmed so that upon the receipt of the second signal produced by the application of the pen point to the X-2, Y-2 position, a straight line is created between the two points, and displayed on the CRT screen. Thus, as is known in the art, the matrix cross points of a pressure sensitive digitizer pad, correspond to the XY positions of an electronic screen readout.
However, there is a tendency for the operator to press down too hard upon the surface of the digitizer pad or tablet which can break the pen, but more importantly, can damage the digitizer pad. These pads are expensive and cost up to $1200. each. Also, if the operator is to draw a second line commencing at the second X-2, Y-2 point mentioned above, the operator can become distracted and have to relocate the exact position of the X-2, Y-2 coordinate in order to properly initiate the creation of the second line.